As the worldwide AIDS epidemic begins its fourth decade, with ~34 million people living with HIV-AIDS around the globe, a cure or vaccine for HIV-1 still eludes us. Fortunately over 30 drugs that belong to seven classes targeting various stages in the life cycle of HIV have improved the overall quality and life expectancy of HIV-infected patients. To date, the most successful anti-viral HIV drugs abrogate functions of HIV enzymes. However, viral diversity from varied clades or poor adherence has led to the emergence of drug resistance preventing the therapeutic control of many HIV infections, warranting the identification of novel targets and therapeutic strategies. Our long-term goal is to develop new, complementary, anti-viral strategies by activating the natural anti-HIV functions of human restriction factors. The APOBEC3 (A3) family of single and double domain cytidine deaminases, particularly A3G, are critical enzymes in this restriction and whose molecular mechanisms may be leveraged in developing such host activated therapeutic strategies. We hypothesize that the molecular interactions and differential specificities of A3s to nucleic acids and HIV-1 Vif provide epitopes that once characterized will provide target sites for future therapeutic development.